Power isnt a concern more than what battery life is.

I have built MIC4680 based switching regulators before, so i could make a good solid 5V 1Amp regulator, that runs outside of the main 5V. Then theres the 12V, Assuming its even necessary, as most accelerators were 5V based?

Definitely NOT 7805ing the thing, too much heat.

But Thats not my goal, the goal is to run an Eth card. Since LC, SE is basically the same, an LC card could run as long as the thing is mapped in the correct slot space. $E